Question: When did Javier Perez de Cuiellar become the UN Secretary-General?
Paraphrase: In what year did Javier Perez de Cuiellar become Secretary-General of the UN?
SPARQL (Wikidata): SELECT ?value WHERE { wd:Q1259 p:P39 ?s . ?s ps:P39 wd:Q81066 . ?s pq:P580 ?value}